Circuit interrupter



Dec. 16, 1952 J. M. WALLACE E'r'Ax. 2,622,165

CIRCUIT INTERRUPTER Filed June 24, 1941 Patented Dec. 16, '1952 CIRCUIT INTERRUPTER James M. Wallace, Braddock, Herbert L. Rawlins, Swissvale, and James M. Cumming and Wayne S. Aspey, Turtle Creek, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 24, 1941, Serial No. 399,452

(Cl. 20G-89) 19 Claims. 1

This invention relates, generally, to electric circuit interrupters and, more particularly, to

automatic reclosing circuit breakers.

The copending application of J. M. Wallace and H. L. Rawlins, Serial No. 374,686, filed January 16, 1941, now Patent No. 2,475,765, July 12, 1949, and assigned to the same assignee as this application, discloses and claims a circuit breaker of this type, and the instant invention is primarily concerned with certain modifications and improvements in the structures of this copending application, and which can be used with other structures. Circuit breakers of this type, in general, are provided with separable contacts in a closed arc chamber, with electro-responsive means for separating the contacts but having a lost motion connection therewith to permit overtravel of the contacts dependent on the pressures developed by the arc. In addition, means are provided for automatically maintaining the breaker contacts separated in response to a predetermined number of successive circuit interrupting operations, and requiring a manual operation to reset the breaker contacts.

One object of this invention is to provide novel operating mechanism for a breaker of the type described.

Another object of this invention is to provide in a circuit breaker of the type described using a liquid arc extinguishing medium, and means utilizing such medium for controlling the rate f movement of the breaker contacts; novel means lcontrolling the supply of fresh liquid to the arcing zone to insure replenishing of the liquid in this zone between circuit interrupting operations.

Another object of this invention is to pro-Vide in an automatic reclosing circuit breaker, novel means for controlling closing movement oi' the breaker contacts.

Another object of this invention is to provide a circuit breaker construction wherein the rating of the breaker may be readily changed.

Another object of this invention is to provide in a circuit breaker of the type described, novel means responsive to a predetermined number of successive circuit interrupting operations for causing the breaker contacts to be maintained in an open circuit position.

A further object of this invention is to provide a circuit breaker of the type described which is compact and relatively simple in structure, yet safe and eilicient in operation.

These and other objects of this invention will .become more apparent upon consideration of the following detailed description of a preferred embodiment thereof, when taken in connection with the attached drawing, in which:

Figure 1 is a substantially central vertical section through a circuit breaker embodying this invention with certain parts thereofV shown in elevation;

Fig. 2 is a partial elevational View of the operating mechanism shown in Fig. 1;

Fig. 3 is a transverse sectional view of the breaker shown in Fig. 1 taken substantially on the line III-III thereof with certain parts omitted.

Fig. 4 is a fragmentary sectional View of the lockout integrating mechanism employed in the breaker shown in Fig. 1;

Fig. 5 is a View like Fig. 4 but showing the parts of the mechanism in a different position from that shown in Fig. 4; and

Fig. 6 is also a partial sectional view illustrating' the mechanism of Figs. 4 and 5 in a still different position of the parts thereof.

The circuit breaker constituting this invention is shown by Way of example as being mounted in a tubular insulating casing 2 which may be of any desired insulating material, preferably porcelain or the like. The casing 2 is provided with a closed bottom and an open top, with the top being closed by a cover assembly 4, and the botttom of the casing having associated there- With a terminal assembly 5. Intermediate the ends of the casing 2 there is provided a cylindrical surface 8, and a supporting bracket I2 is adapted to be clamped around this cylindrical surface with resilient material I0 interposed between the clamp I2 and the outer casing wall to prevent damage thereto.

The terminal assembly 6 at the bottom of the casing includes a terminal bolt I4 of conducting material adapted to extend through a substantially central aperture in the bottom casing wall, and the bolt is provided with an enlarged head I8 interiorly of the casing, Withpacking -material 20 interposed between the head IB and the bottom wall of the casing. A nut 22 and washer 24 cooperate with bolt I4 to retain the samein position, and a conductor 28 may be secured to the bolt, for example, as by a second nut 2B. Bolt I4 is preferably provided with a substantially central bore 30 for the purpose of draining casing 2, the lower end thereof being adapted to be closed by a screw-threaded closure plug 32.

The upper end of casing 2 is ribbed, and a supporting flanged ring 34 s adapted to be secured to this ribbed portion of the casing, for

example, as by cast metal, or the like, 36. Supporting ring 34 is adapted to have cover assembly 4 secured thereto in any desired manner, not shown.

The casing and terminal structure 6 described above are substantially identical with those more particularly described and claimed in the abovementioned copending application of H. L. Rawlins and J. M. Wallace, and in their copending application, Serial No. 346,300, led July 19, 1940, now Patent No. 2,318,421, issued May 4, 1943, to the same assignee as this application.

Cover assembly 4 comprises an integral casting having a flange 33 formed integrally with the lower end thereof and adapted to seat on the upper end wall of casing 2 and extend over the interior of the casing. Flange 33 is also provided with integral outwardly extending ears (not shown) adapted to be bolted to ears formed on supporting ring 34. The cover assembly casting is provided with a hollow portion including the top wall liti, side walls 42, d3, and end walls M and d5, with the bottom of the hoilow portion being open and located over the open top of casing 2. At one upper corner of the hollow portion of cover assembly ll, an inclined wall is provided with a threaded aperture for cooperation with a threaded filler plug de, by means of which casing 2 may be filled with an arc extinguishing iluid. Top wall lil of the hollow portion of the cover assembly is extended beyond the hollow portion and slightly inclined downwardly as at 48 to form the top wall of a sleet hood portion having side walls 52 and 53. The top wall i3 of the hood portion terminates in an angularly downwardly extending lip di), for a purpose to be hereinafter described.

As appears from Figs. 1 and 3 of the drawing, ange 33 of the cover assembly 4 has portions which extend over the open top of casing 2, and these portions are adapted to insulatingly support the circuit breaker contacts and operating mechanism, for example, as by the tubular insulating spacer sleeves Eid. The spacer sleeves 54 have the opposite ends thereof threaded for cooperation with screws 56 and 53, to secure the spacers to flange 38 and the upper leg H36 of a U-shaped supporting frame 6b, respectively. The other leg lll of U-shaped frame 60 is secured to one end of a generally rectangular frame 64', and the other end of thisV frame is preferably formed integral with the top cap 65 of an interruptor chamber 6B.

The interruptor chamber E53 includes an insulating tube 'Hl of iiber or the like, having one end threaded into top cap 66, and having the other end threadedly received in a bottom terminal cap 14. Top cap et is provided with Aa substantially central aperture 69 for closely slidably receiving a contact piston rod 12, and the cap is also provided with spaced outlet apertures 13 adapted to be controlled by a sliding valve plate HB2, normally biased by coil compression spring IM into engagement with the adjacent end of insulating tube lil. The lower end cap M of the interrupter chamber is provided with inlet passages le, and with a substantially centrally located threaded aperture for receiving the threaded end of an adjustable .xed contact 18 which is secured in position, for

example, as by a lock nut Si). The outer end of end cap 'i4 is reduced in size to form a shoulder 82 on which is seated one end of a coil compression spring 8d with the other end ofY this spring bearing against the head l of terminal bolt i4.

Spring 84 should be of some good resilient conducting material, such, for example, as a copper alloy or the like.

The lower end of contact piston rod l2 is provided with a socket for receiving the upper end of contact rod 86, secured in the socket, for example, as by a rivet 86. The lower end of contact rod 86 is enlarged to form a contact head 9b. A, liquid directing piston 92 is provided with a central aperture Si so that the piston may be slidabl'y mounted on contact rod 86 for movement between contact head and the lower end of contact piston rod 12. Ther lower end of contact piston rod 'l2 is counterbored to receive a coil compression spring 93 which. normally operates to bias liquid directing pistonl92 towards contact head Eil. As shown, piston 92 is provided centrally with a hollow portion to which access is obtained by means of a plurality of top apertures Sil, and a single lower aperture 95 concentric with contact head 90 so as to form an annular liquid passage therewith. Liquid director piston 92 may have a peripheral slotfor the reception of a piston ring 96 to prevent leakage of liquid between the piston and inner wall of tube 10. A stop ring 93 is secured in position between the lower end of insulating tube 'l0 and lower end cap 'M and, as shown, projects inwardly so as to form a stop for liquid director piston 92, so that when the contacts are closed, the piston is maintained in a position intermediate the limits of its movement on contact rod 86. The inlet apertures '1li in cap 'I4 are adapted to be controlled by a check valve plate |00 freely mounted between the end wall of end cap 14. and stop ring 95. The interrupter chamber B8 described above is subsantially identical with that` described and claimed in the above-mentioned copending application oi J. M. Wallace and H. L. Rawlins, Serial No. 374,- 686, now Patent No. 2,475,765- except that in the interruptor chamber herein described, valve plate vH12 is spring biased in one direction, rather than being frictionally associated with contact piston rod 12 as in the said copending application.

The operation of the interrupter chamber herein disclosed and illustrated. is substantially the same as that in the above-identified copending application .and comprises briefly utilization of fluid pressures generated by an arc drawn, to obtain contact separation. This is accomplished by the instant structure because it will be observed that as soon as contact piston rod 'l2 is moved upwardly and contact head Se moves out of engagement with Xed contact 'I3 to strike an arc, the action of such an arc on the arc extinguishing liquid within the chamber, such, for example, as oil or the like, will decompose the same to generate a gas which will build up a pressure within chamber 68. As soon as this pressure builds up, it will obviously force check valve plate |00 and valve plate H32 outwardly relative to insulating tube 10 to close both the inlet and outlet apertures 16 and 13, respectively. Outward movement of valve plate m2 readily occurs because the upper side of this plate is vented by aperture |03. Accordingly, such pressures within the chamber will act on contact piston rod 'l2 in a piston-like manner to force the same to move outwardly of the chamber, and thereby increase the contact separation. In the upward movement 0f contact rod 86, liquid director piston 92 remains stationary until contact head 90 engages the upper wall of the director to thereby draw the are out to an optimum length before moving the director to cause a flow of liquid through apertures 941 and 95 into the arc to extinguish the same. Contact piston rod 12 and contact rod 8B will be moved outwardly by the pressure developed within arc chamber 68 until the combined action of attenuation of the arc and flow of liquid therethrough cause extinction. As soon as the arc is extinguished, the contact piston rod 12 is adapted to be moved downwardly towards xed contact 18 in a manner to be hereinafter further described, and since pressure is no longer being generated within the chamber, spring |04 will be free to move valve plate 102 downwardly to open outlet passages 13 and permit exhaust of gases and used liquid out of the upper end of the are chamber. This upflow of gas and used liquid from the chamber will be taken care of by an vin-flow of fresh liquid through inlet apertures 16 which will cause check valve plate Iil to be unseated due to the pressure at the bottom of the casing because of the head of liquid therein, and especially because of the difference in pressure due to the difference in the head of liquid between inlet apertures 16 and outlet apertures 13. Consequently, it can be seen that the fluid pressure developed by the arc is utilized in this interrupter to obtain contact separation, and that during a closing operation of the breaker contacts, the used arc extinguishing fluid within the chamber is replaced by fresh fluid from casing 2.

As previously stated, the substantially U- shaped supporting frame member 60 is secured to the upper end of rectangular supporting frame 54, and the frame member G is for the purpose of supporting a solenoid coil |12. The upper and lower legs 196 and H13 of supporting member 60 are [connected by spaced integral legs IB positioned at one side thereof, so that the solenoid coil ||2 may be assembled with support 60 by merely slip-ping the entire coil between legs IGS and 108 through the open side of support ED. The legs IBG and |08 of the U-shaped frame |59 are provided with aligned apertures adapted to coincide with the central bore provided in solenoid coil 1|2, and a securing sleeve H4, of insulating material, is adapted to be inserted through the aperture in leg |08 of the U-shaped support 68 into engagement with a shouldered plug |16 seated against a shoulder provided about the aperture through leg 106 of U-shaped supporting frame 6|). Securing sleeve ||4 is maintained against movement downwardly from the supporting frame 6U, as viewed in Fig. 1, b-y the connection of rectangular frame 64 thereto, inasmuch as the end plate |18 of this frame is provided with a shouldered aperture, with the adjacent end of securing sleeve It seated on the shoulder of this aperture to prevent movement thereof with respect to U-shaped frame 6|). Frame 69 is of magnetic material to form a stationary frame for coil I|2 as well as a support therefor. Rectangular frame 64 is secured to the lower leg 108 of LI-shaped frame |50, for example, as by screws 62, or the like. It will be noted that solenoid coil 112 is provided with a plurality of taps IIS which are connected to different sections of the coil and located away from the connecting legs I|0 of the U-shaped support 60, at the open side thereof so as to be readily accessi-ble for the purpose `of changing the coil connections when desired. Rectangular subporting frame 64 is provided with the side plates |20 integral with top plate IIB at one end thereof, and with top cap 66 for the interrupter chamber at the other end thereof.

The upper end of contact piston rod 12 is peripherally grooved as at |22 to form a notch and a latch projection |24 at the upper end thereof, for cooperation with a latch lever |26. The latch lever is adapted to be pivctally mounted on top end cap 66 of the interrupter chamber, for example, as by a pivot pin |28, and a coil spring |30 is wound about pivot pin |28 with the ends thereof engaging end cap 65 and latch lever |26, respectively, for biasing the latch lever in a clockwise direction about its pivot, as viewed in Fig. l. The latch lever is provided with a plurality of latch lugs |32 and |34 for cooperation with the latch projection |24 on the upper end of contact piston rod 12, and with the core 'of solenoid coil |12. A contact operating rod |36 is rigidly secured to contact piston rod 12 and extends from the upper end thereof through a sleeve 131 extending through the central opening of solenoid coil |12 and securing sleeve I|4. The lower end of sleeve |31 is enlarged as shown at 138 to receive the upper end of a coil compression spring |44, with the lower end thereof bearing against the bottom wall of a tubular solenoid core member 14%. The tubular solenoid core HB, which is of magnetic material, has the bottom wall thereof apertured to be slidably mounted on contact operating rod 136, and has adjacent the upper end thereof a peripheral inwardly extending rib |42 of a size to closely engage the outer surface of enlarged portion |38 of sleeve 131. Adjacent the lower end of solenoid core 148 are radially directed vent apertures |46, for a purpose to be hereinafter described.

In the operation of the mechanism thus far described, it will be apparent that upon the occurrence of predetermined circuit conditions, solenoid coil ||2 will become sufficiently energized to attract core I and cause it to move upwardly on operating rod |36 and compress spring |613 between the core and sleeve 131. Furthermore, because of the close fit between core |40, securing sleeve IM and enlarged portion |38 of sleeve |31, and since these parts are all immersed in the arc extinguishing fluid, it will be obvious that upward movement of core |40 will be relatively slow because of the necessity of displacing the uid within securing sleeve I |45 through the relatively small clearance between the core and sleeve. However, after sufcient movement of the core upwardly so that rib |42 clears the upper end of enlarged sleeve portion I 38, there will then be a relatively large annular passage through core |40 and outlet apertures 146 for liquid entrapped in securing sleeve IM, so that further movement of core 14) upwardly will take place at a relatively rapid rate. During this rapid movement of the core, the bottom wall thereof will engage the lower end of enlarged sleeve portion |38 to cause movement of the sleeve upwardly with the core, and engagement of the upper end of the sleeve with shoulder |41 formed on contact operating rod 136, will thus yquickly separate contact head 9ii from fixed contact 18. This movement of contact head by solenoid core I4!! away from fixed contact 18 need be but a small amount, because as soon as the contacts are separated sufficiently to draw an arc, the pressure generated by such an arc operates to increase the contact separation sufliciently to extinguish the arc. Obviously because of the sliding connection of solenoid core |40 with respect to contact operating rod |36, the

contact operating rod and Contact head 99 are permitted to have a considerable over-travel independent of solenoid core |49 in response to pressures built up within the interrupter charm ber60. As soon as the arc is extinguished and the pressure drops within interruptor chamber 68, contact operating rod |39 is permitted to move downwardly to reclose the contacts. However, its downward motion is halted by engagement of latch projection |24 at the top of contact piston rod 12 with upper latch lug |32. In the meantime, solenoid core |49 returns Very slowly under the biasing forces of gravity and spring |44, to the position shown in Fig. 1 because of the dashpot action thereof in securing sleeve i lil, so that considerable time must elapse until the solenoid core moves down into engagement with the upper end of latch lever |29, and thereby cause counterclockwise rotation of the latch lever to disengage its upper lug |32 from contact piston rod projection |24. This permits the projection |24 to drop down slightly with contact 4operating rod |35, and into engagement with the lower lug |34 on latch lever |26, where it isheld until further downward movement of solenoid core |49 causes further counterclockwise movement of the latch lever until projection |24 is released from lug whereupon the contact head 99 is permitted to move into engage ment with fixed contact 18. Incidentally, it will be noted that upper lng |92 of latch lever |26 serves as the support for preventing undue downward movement of solenoid core The reason why a plurality of lugs |32, |34 are provided on the latch lever to successively halt downward movement of contact head 95 towards xed contact 18, is that it is necessary to maintain the contacts separated during the time delay period before reclosure, a sufficient distance apart so that the dielectric therebetween will be capable of safely withstanding circuit voltage. Because of contamination and deterioration of the dielectric on the interruption of high current arcs, this distance is quite large. On the other hand, it is desired to make the time delay between a circuit interrupting operation and a reclosure of the circuit as long as possible with the available time delay means including the dashpot comprising solenoid core |40 and securing sleeve H4. Lug |32 on the latch lever, therefore, is positioned to engage the moving contact to hold it separated from iixed contact 18 a distance corresponding to the safe gap therebetween according to the dielectric being used. If lug |34 were not also provided on the latch lever, then the time delay between a circuit interrupting operation and a reclosure of the breaker contacts would be too short, and accordingly, to lengthen this period, the second lug |34 is provided for momentarily delaying reclosure of the breaker contacts after release of the moving contact from lug |32, to thereby obtain a longer time delay in reclosing without undue danger of ilashover, inasmuch as the period of time which lug |34 operates to maintain the breaker contacts separated is so short that ionization of the path between the breaker contacts does not have time to be completed prior to reclosure of the contacts. Also on interruption of low currents, the pressure may be insunicient to move contact projection |24 as high -as latch lug |32 and since the dielectric will not be unduly impaired by low current interruptions, engagement with latch lug |34 will provide a safe gap between the contacts while using full time delay on reclosure. This feature of the invention together with the special construction of arc chamber 68-are disclosed and claimed in application Serial No. 562,798, iiled November 10, 1944, now Patent No. 2,442,477, June 1, 1948, which is a division of this application.

The upper end of contact operating rod |36 is pivotally secured as by pivot pin |50 to one end of a pair of insulating links |48, with the other endsof the `links, being connected to an angled crank lever |52, for example, as by the pivot pin |53. `Cranklever |52 is pivotally mounted at its other end on a shaft |54 extending across the hollow portion of the top cover casting, and its outer ends are mounted in apertures provided in the side walls 42 and 43 of the cover hollow portion, with the outer ends of these apertures being yclosed by screw plugs |56 to prevent relative endwise movement of shaft |54'. Angled crank lever |52 is rotatably mounted on shaft |54, and a generally U-shaped yoke |58 has the leg portions thereof also rotatably mounted on shaft |54, with one'leg of yoke |58 pivotally connected to one end of toggle link-s |60 by a pivot pin |62, and the other ends of these toggle links being pivotally connected at |64 to a toggle lever |66, which is, in turn, secured on the squared end of a shaft |68 rotatably mounted in an angled p0rtion of end wall 45 of the cover assembly in a bearing sleeve |12, by a bolt |10, which also acts to secure an operating handle |14 to the other squared end of shaft |68. Operating handle |14 is pro-vided at the outer end thereof with a hook -eye aperture |16 for the reception of a hook stick or other operatingr member. Actuating handle `|14 is limited in its movement in a counterclockwise direction by a stop screw |16 which may be secured in an adjusted position, for example, as by a lock nut |80.

A pair of concentric coil springs 182 and |84 are provided about shaft |54 within the hollow portion of the cover assembly 4, with one end |86 of the outer large diameter coil spring 84 engaging flange 38 of the cover assembly, and the other end |88 thereof engaging the connecting portion |89 of yoke |58, to thereby bias the yoke for movement about shaft |54 in a counterclockwise direction. This movement of the yoke is normally prevented by virtue of the toggle formed by links |60 and |66 being below their deadcenter position when actuating handle |14 is in engagement with stop screw |18. One end |90 of the smaller diameter inner coil spring |82 is extended to engage the angled portion of crank lever |52, and the other end of this spring also engages the connecting portion |99 of yoke |58, so that when the yoke is locked by toggle levers |60 and |66 against movement in a counterclockwise direction, biasing spring |82 will operate to bias crank lever |52 downwardly or in a clockwise direction relative to shaft |54, to thereby bias contact actuating rod |36 and contact head 90 downwardly, and cause engagement of the contact head with fixed contact 18.

The circuit through the interruptor herein disclosed extends from a terminal bracket |94 secured to the top cover assembly, for example, as by a screw |98 with the bracket having a terminal socket |96 for the reception of a line conductor, through the cover casting, by way of a conductor 209 to one tap ||9 of solenoid coil ||2, through the coil, conductor 202 to contact piston rod 12, contact rod 86, contact head 99, xed contact 18, end cap 14, compression spring 84, terminal bolt I4, to another line conductor 28.

Thus, it can be seen that the solenoid coil ||2 is `connected in series in the circuit including the breaker contacts, and as shown, the whole coil is connected in series, inasmuch as the end taps of the co-il are used, and, therefore, the connection is for the lowest rating of the breaker which can be obtained with the coil employed, inasmuch as the maximum flux generating capacity of the coil is employed to thereby obtain sufficient force to separate the contacts on relatively low currents. To obtainhigher current ratings, it would be merely necessary to connect conductor 202 or 200 to other taps H9 of the coil to utilize smaller portions of the coil Winding. It will be noted that the entire circuit breaker mechanism including the breaker contacts and interrupting chamber are supported as a unit with the casing cover assembly 4, so that they may be removed with the cover from the casing when desired by merely unfastening the securing means of the cover to support 34 on the casing. Another feature of the particular supporting means for the circuit breaker mechanism illustrated, is the specic support of the solenoid coil permitting ready replacement thereof by another similar coil, or by a coil having a different number of turns t thereby change the available ratings of the breaker. In order to remove coil ||2, it is merely necessary to remove screws 62 holding U-shaped frame 60 and rectangular frame 64 together. This permits securing sleeve I |4 to drop downwardly out of U-shaped frame 60, and then by removing one pivot pin, for example, the pivot pin |50, the entire contact operating rod and sleeve |31 can be slipped out of U-shaped frame 60 through apertures in legs |06 and |08 of the frame, whereupon coil ||2 may be slipped laterally out of the open side of U-shaped frame 60. To insert a new coil, it is simply necessary to slide it in the open side of U-shaped frame 60 until the bore therethrough is aligned with the apertures in legs |06 and |08 of the frame, whereupon contact actuating rod |36 and securing sleeve |4 may be inserted through the apertures and through thebore in the coil, and rectangular frame 64 secured to the lower leg |08 of the U-shaped supporting frame to thereby firmly secure the solenoid coil in operative position. Consequently, in order to remove the coil, it is only necessary to remove two screws 62, and one pivot pin |50. This feature of the invention is disclosed and claimed in application Serial No. 561,384, iiled November l, 1944, now Patent No. 2,468,852, May 3, 1949, which is a division of this application.

The operation of contact biasing spring |82 mounted on shaft |54 in cover assembly 4 is believed to be obvio-us from the foregoing. In other words, when the circuit is interrupted by energization of solenoid coil ||2 suii'iciently to raise core |40 and separate the contacts against the bias of spring |82, this spring will be effective as soon as the circuit is interrupted to move the contact operating rod and contact head 90 downwardly towards fixed contact 18, until projection |24 on Contact piston rod 12 is engaged by latch lug |32, whereupon reclosurey of the contacts will be delayed until the latch is released by solenoid core |40 in the manner previously described.

In the event an overload occurs on the circuit which is not self-clearing but continues after a predetermined number of successive interrupting operations, there is provided means for tripping the toggle which normally prevents rotation of yoke |58, so that spring |84 becomes effective to rotate the yoke in a counterclockwise direction to the dotted line position shown in Fig. 1 and, consequently, raise crank lever |52, by engagement of the cross bar |89 of the yoke with a projection |9| on the lever, together with contact actuating rod |36 and contact head 90 to a position wherein the contact head is maintained out of engagement with fixed contact 18, because coil spring |82 will be ineifective to reclose the contacts. The means for tripping the toggle includes a cylindrical tube 204 threadedly mounted in the upper leg |06 of U-shaped support 60, and provided with an inlet aperture 208 in the bottom wall thereof controlled by a ball-check valve 2|0 to permit now of liquid into tube 204, but preventing out-flow of liquid. A piston member 206 is slidably mounted within cylindrical tube 204, and the upper end thereof is provided with a plurality of spaced peripheral grooves 2|4, 2|6, and 2|8, respectively, to form a ratchet-like por tion on the piston accessible through a side opening 2|2 in cylindrical sleeve 204. A pawl guide rod 220 is also secured to leg |06 of U-shaped support 60 between cylindrical sleeve 204 and contact operating rod |36, for guiding a substantially U-shaped pawl member 222, having the connecting portion thereof slotted, as shown at 224 to receive the contact operating rod and with the ends of the slot extending into the legs of the U-shaped pawl but reduced in width, as shown at 226, to more closely t guide rod 220. Contact actuating rod |36 is adapted to extend through the slot 224 so that the bottom portion of the pawl seats on flange 232 formed on the upper end of sleeve |31 slidable on the contact actuating rod. Guide rod 220 is formed with an intermediate shoulder on which a Washer 228 is adapted to be seated, with a coil compression spring 230 engaging between washer 228 and the lower leg of U-shaped pawl 222 to normally maintain .the pawl in the position shown in Fig. 4.

In the operation of the circuit breaker, it will be observed that each time solenoid core |40 is drawn upwardly to open the circuit and engage the lower end of enlarged portion |38 of sleeve |31 to move the same upwardly, that it will cause a tilting of pawl 222 against the bias of spring 230, so that the upper end thereof moves towards `piston 206 and engages one of the grooves in the pawl portion thereof, so that continued upward movement will move the entire piston upwardly and thereby unseat ball-check valve 2|0 and cause a predetermined amount of liquid to be drawn in the lower end of sleeve 204. As so'on as the circuit is interrupted, and the contact actuating rod and associated parts are moved downwardly by biasing spring |82 in the manner previously described, compression spring 230 on guide rod 220 is operative to withdraw the upper leg of pawl 222 from the notch 2|4 in piston 206, so that the piston remains at the position to which it has been moved, while the contacts are reclosed. Now if the fault on the circuit has been removed, piston 206 will gradually sink to the position shown in Fig. 4 by displacement of the liquid below the piston through the relatively small clearance between the piston and cylindrical sleeve 204, so that eventually it will attain its original position shown in Figs, 1 and fr. However, in the event the fault in the circuit has not cleared upon the rst reclosure vof the breaker contacts, they will again be opened by solenoidL H2, and this time pawl 222 will engage notch 2|6 in piston 206, as shown in Fig. 5, inasmuch as the piston will not have had time to sink to its original position and the piston will be moved upwardly to the position shown `in Fig. 6. ofthe drawing. As soon as the arc is extinguished, the contacts will again be reclosed by biasing spring |82, and if the fault has cleared, piston 200 will again slowly sink to its original position as before. However, if the fault has not cleared, before piston 206 has an opportunity to sink much below the position shown in Fig. 6, the contacts will again be opened, and this time pawl 222 will be pivoted into engagement with the lower notch 218 in piston 20G and cause thesame to be moved upwardly a further amount and into engagement with the knee of the toggle formed by levers |60 and |60 to move the knee of the toggle overcenter, thereby releasing spring |84 and permitting the same to rotate yoke |56 and move the toggle levers and contact operating rod to the dotted-line position shown in Fig, 1 of the drawing wherein the breaker contacts are maintained by spring |34 in an open circuit position.

It will be observedvthat ordinarily actuating lever |14 is maintained entirely within the hood formed integral with top cover assembly 4, but upon tripping of the toggle constituted by levers |60 and |66, the actuating lever VM will be moved in a clockwise direction about its pivot axis to project Abelow the hood, and thereby give a readily visible indication of the fact that the breaker contacts are now maintained in an open circuit position. When piston 206 has tripped the toggle, it will be observed that since contact operating rod |36 is maintained in an upper position, pawl 222 will be maintained in engagement with notch 2|8 on piston 206 to maintain the piston in its uppermost position. Accordingly, when itis desired to manually reclose the breaker contacts by movement of operating lever |`|4 in a counterclockwise direction 'to reset the toggle levers to the yposition shown in full lines in Fig. l, it will be observed in the rst place, thatI in the event it is thus attempted to close the circuit while an overload is present, that the breaker is trip-free in that it is free to open against the bias of contact biasing spring |62 irrespective of the position of actuating lever |74. In the second place, it will be noted that since piston 206 has had but a little time to move downwardly from its outermost position with respeci; to cylindrical sleeve 204, that in the event the breaker is reclosed manually upon an overload in the circuit, that on the consequent circuit interruption and movement of the contact operating rod and associated parts upwardly, pawl 222 will be caused to engage the lower notch 2 I8 of'piston 206 to thereby move the toggle overcenter and again permit spring |94 to maintain the contacts in an fopen position.

Thus, it can be seen that the circuit breaker herein disclosed is capable of automatically opening the circuit with an inverse time delay due to the dashpot action of core |40 in securing sleeve 4, and yet the contacts are separated with a relatively fast action due to the venting of the dashpot formed vby core |40 and sleeve ||4 adjacent the end of its stroke. This feature is the invention of J. M. Wallace and is more particularly disclosed and claimed in his copending application, Serial No. 399,453, iiled June 24, 1941, now Patent No. 2,333,604, issued November 2, 1943, to the same assignee of this invention. Following a circuit interrupting operation, the breaker contacts are automatically reclo'sed with a time delay also due to the dashpot action of core |40 and sleeve `||`4, whilelrnain taining substantially to adjacent the end of the timed period a safe gap between the breaker contacts. number :of closely successive circuit interrupting operations, novel means are provided for maintaining the breaker contacts man open position, which includes a biasing means normally held inactive by a toggle which is moved overcenter by a piston actuated a predetermined amount upon each interrupting operation, The arc chamber herein disclosed is provided with an outlet valve which is positive in-operaticn, and

ie electro-responsive solenoid contact opening means is supported in a manner to render the same readily replaceable, and is provided with a plurality of taps so that the rating of the breaker may be readily changed. The specific arrangement of the contactclosing spring and the spring for maintaining `the contacts separated is vespecially important with respect to space considerations and eliciency of operation.

An operation counter 234 is adapted to :be mounted on the end wall 45 of the hollow lportion of cover assembly 4 and to be located beneath the hood portion thereof soas to be readily visible from the exterior of the breaker. while protected from the elements by the hood. This operation counter may be of any well known type provided with an actuating crank lever 236, mounted on an operating shaft extending. through the angled portion of wall 45 like shaft |66, and withcrank 236 pivotally connected to an operating link238, which, in turn, is connected to pawl 222, so as to actuate the counter on each circuit interrupting operation of the breaker. VThe connecting link 238 is provided with an insulating portion 250 to insulate the counter from pawl-222.

There is preferably provided within the hollow portion of cover assembly 4 in a socket 242 pro vided therefor on top wall 40, a lightning arrester assembly, which may be oany well known type including electrodes 256 spaced'by an insulating plate 258 to form a gap in series with a porous block 260, in the circuit between top wall '40 of the cover and terminal 244 of the assembly. A tubular insulating sleeve 262 is positioned be-` tween the-assembly and the side wall of socket 242, and insulating disk 210' supports terminal 244, and is secured to the cover assembly 4 by screws 266, with a sealing gasket 264 therebetween to maintain the arrester assembly in socket 242. A shunt 268 connects terminal 244` and a contact plate 21|, and this rplate is maintained in contact with block 260 by a spring 212. The arrester terminal 244 is connected by conductor 246 to the top leg |06 of U-shaped frame 60 to thereby form a circuit bypassing solenoid coil I I2. This obviously will preventthe solenoid coil from opening the :breaker contacts in response to surgesinasmuch as the coil willco`- operate with the shunt circuit through' the arrester assembly to bypass such surgecurrentsl around the coil and limit the voltage across the coil insulation, and such surges will -be'ineifective to cause a circuit interrupting'operation of the breaker. The arrester assembly herein disclosed utilizes asingle series porous'block and gapof the type shown in theplural series block and gap arrestershown in the patent to L. R.Ludwig, et al., No. 2,135,085, issued November 1, 1938. It will be understood that plural series porous block and gap assemblies may be used with this 13 crcutbreaker. if desired. This feature of the invention is disclosed and claimed in our divisional application, Serial No. 737,874, filed March 28, 1947, now Patent No. 2,575,739, November 20, 1951, and assigned to the same assignee of this invention.

Also positioned beneath the hood portion of the cover assembly is a tubular sight gauge glass 250, held in position against an integral lug 248 on end wall 45 of the cover assembly, by an apertured threaded plug 249, and an indicating rod 252 is slidably mounted through the apertured plug and tubular sight glass, and is provided with a float 254 secured to the lower end thereof within casing 2 so that the level of liquid within casing 2 may be readily determined from the exterior thereof by inspection of the sight glass beneath the hood portion of the cover assembly.

Thus, there is provided in a single unit an automatic reclosing circuit breaker characterized by its ability to automatically maintain the breaker contacts in an open circuit position in response to faults which continue a predetermined period of time, and by its inverse time current tripping characteristics with predetermined time delay in reclosing of the circuit, together with means incorporated in the unit to protect the coil insulation and prevent operation of the breaker in response to the occurrence of surges in the circuit. Moreover, the cover assembly for the breaker casing 2 is arranged with a sleet hood portion at one side thereof to conceal an operating handle which is projected into View upon lock-open operation of the .breaker contacts to indicate this condition, and also houses liquid level indicating means, as well as means for indicating the number of breaker operations.

Having described a preferred embodiment of this invention in accordance with the Patent Statutes, it is desired that it be not limited to the particular embodiment herein disclosed, inasmuch as it will be obvious, particularly to persons skilled in the art, that many changes and modications may be made in this particular embodiment without departing from the broad spirit and scope of the invention. Therefore, it is desired that the invention be interpreted as broadly as possible and that it be limited only by the prior art and by what is-expressly set forth in the following claims.

We claim as our invention:

1. In an automatic reclosing ycircuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, normally inactive means adapted when activated to prevent closure of said contacts, control means for rendering said lastmentioned means active including fluid piston and cylinder members, means directly mechanically engageable with one of said members onlir during separation of said contacts to move said one member in one direction relative to the other the same predetermined amount on each circuit interrupting operation, said one member being biased to slowly move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number of successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure of said contacts.

2. In an automatic reclosing circuit breaker, a relatively stationary contact, a contact rod slidably movablefor causing engagement and disengagement of a movable contact supported thereon with respect to said stationary contact, electro-responsive means for moving said rod in a direction to separate said contacts, means responsive to a circuit interrupting operation for moving said rod in an opposite direction to automatically reclose said contacts, normally inactive means for preventing closure of said contacts, control means for rendering said last-mentioned means active including iiuid piston and cylinder members, means responsive to a circuit interrupting operation for moving one of said members in one direction relative to the other a predetermined amount, said last-mentioned means including a ratchet formed on said one member, a pawl guide extending generally in the direction of movement of said one member, a pawl slidably and tiltably mounted on said guide, means biasing said pawl out of engagement with said ratchet, a shoulder on said contact rod engageable with said pawl upon movement thereof in a direction to separate said contacts for tilting said pawl into engagement with said ratchet and moving said pawl along said guide and said one member in one -direction relative to the other member a predetermined amount, said one member being biased to slowly move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number of successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure of said contacts.

3. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separatingv said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, resilient means for maintaining said contacts separated, overcenter toggle means for releasably maintaining said resilient means in an inactive condition, and means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said resilient means whereby to maintain said contacts separated.

4. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, resilient means for maintaining said contacts separated, overcenter toggle means for releasably maintaining said resilient means in an inactive condition, means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said resilient means whereby to maintain said contacts separated, and one lever of said toggle means including an operating handle extension for resetting said toggle means.

5. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for causing engagement of said contacts, resilient means for maintaining said contacts separated, overcenter toggle means for releasably maintaining said resilient means in an inactive condition, means responsive to a predetermined number ci circuit interrupting operations to cause movement of said toggle means overcenter to release said resilient means whereby to Vmaintain said contacts separated,` said last-mentioned means including fluid vpiston and Acylinder' members, vmeans enacaaiec ageable with cne of said members only upon separation of said contacts to move said one member in one direction relative to the other a predetermined amount, said one member being biased to slowly move in the opposite direction to itsnormal position, and said one member upon movement in said one direction an amount determined by a predetermined number of successive interr-upting operations adapted to. engage said toggle means to release said resilient means, manual means for resetting. said toggle means to permit said contacts to move into engagement and release said one member, whereby said resilient means will be released in the event of the occurrence of a circuit interrupting operation upon manual resetting of said biasing means.

6. In a circuit breaker, separable contacts, electro-responsive means for separating said contacts, concentric coil springs one of Whichobiases said contacts into engagement, means releasably maintaining said other coil spring inactive, said other spring when released being effective to maintain said contacts separated, and means responsive to a plurality of successive circuit interrupting operations for releasing said other coil spring.

7. In a circuit breaker, separable contacts, electro-responsive means for separating said contacts, a first resilient means reacting between a movably mounted support and at least one of said contacts, means releasably maintaining said support against movement whereby said rst resilient means is eiectve to cause engagement or said contacts, a second resilient means biasing said movable support in a direction to cause said contacts to be separated, and means responsive to a plurality of successive circuit interrupting operations for releasing said movable support formovement by said second resilient means.

8. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, normally inactive means for preventing closure of said contacts, control means for rendering said last-mentioned means active including fluid piston and cylinder members, an inlet for said cylinder member, a check valve for said inlet, means responsive to a circuit interrupting operation for directly mechanically engaging one of said members to move it in one direction outwardly relative to the other a predetermined amount to cause the same predetermined amount of fluid to be drawn into said cylinder member on each circuit interrupting operation, said one member being biased to slowly move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number oi successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure of said contacts.

9. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, normally inactive means adapted when activated to prevent closure of said contacts, control means for rendering said lastmentioned means active including fluid piston and cylinder members, means responsive to a circuit interrupting operation for mechanically engag- `ing one of said members to move said one member in one direction relative to the other the same 16 predeterminedamount on eaclrcircuit interrupts. ing operation, said one member being biased to slowly move in the oppositedirection to its normal position, and said one member uponmovement in` said one direction an amount determined by apredetermined number of successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure `of said contacts.

10. In an automatic reclosing circuit breaker, separable contacts, electro-responsive meansifor separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, normally inactive means adapted when activated to prevent closureof said contacts, control means for rendering said lastmentioned means active including fluid piston and cylinder members, means including paw-1 and ratchet means cooperable with one of said members only during separation of said contacts to move said one member in one direction relative tothe other the same predetermined amount on each circuit interrupting operation, said one member being biased to slowly move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number of successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure lof said contacts.

ll. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, normally inactive means adapted when activated to prevent closure of said contacts, control means for rendering said lastmentioned means active including uidpiston and cylinder members, means having lost motion with said contacts responsive to a circuit interrupting operation for mechanically engaging one of said members to move said one member in one direction relative to the other the same predetermined amount on each circuit interrupting operation, said one member being biased to slowlyv move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number cf successive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure of said contacts.

i2. In an automatic reclosing circuit breaker, a relatively stationary contact, a contact rod slidably movable for causing engagement and disengagement of a movable contact supported thereon with respect to stationary contact, electro-l responsive means ior moving said rod in a dlrection Vto separate said contacts, means responsive to a circuit interrupting operation for moving said rod in an opposite direction to `automatically reclose said contacts, normally inactive means for preventing closure of said contacts, control means for rendering said. last-mentioned means active including nuid piston and cylinder members, means responsive to a circuit interrupting operation for moving one of said members in one direction relative to the other a predetermined amount, said last-mentioned'means including a ratchet formed on said one member, a pawl guide extending generally in the direction of movement of said one member, apawl slidably and tiltably mounted on said guide, means biasing said pawl out of engagement with said ratchet, pawl actuating means having'lost motion with respect to said contact rod for engaging said pawl upon movement of said contact rod in one direction to tilt said pawl into engagement with said ratchet and move said pawl along said guide and said one member in one direction relative to the other, means limiting movement of said one member by said lpawl upon a single circuit interrupting operation to a predetermined amount, said one member being biased to slowly move in the opposite direction to its normal position, and said one member upon movement in said one direction an amount determined by a predetermined number ofsuccessive interrupting operations adapted to engage said normally inactive means to render the same active to prevent reclosure of said contacts.

13. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, biasing means for maintaining said contacts separated, overcenter togglegmeans for releasably maintaining said biasing means in an inactive condition, means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said biasing means whereby to maintain Said contacts separated, and manually operable means operatively associated with said toggle to reset the same.

14. In a circuit breaker of the type described, a supporting casing having an open end and a closed end, a cover for the open end of said casing having a hollow portion overlying and opening toward said casing, a circuit breaker mechanism in said casing and supported from said cover to form therewith a removable unit, said mechanism including separable contacts and electro-responsive contact opening means, and resilient means supported in the hollow portion of said cover for maintaining said contacts separated, overcenter toggle means for releasably maintaining said resilient means in `an inactive condition, and means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said resilient means whereby to maintain said contacts separated.

15. In an automatic reclosing circuit breaker having separable contacts, means responsive to predetermined circuit conditions for causing separation of said contacts to open the circuit, means responsive to a circuit interrupting operation for automatically causing a circuit closing operation of said contacts, means rendered operative inrespcnse to a predetermined number of closely successive circuit interrupting operations for automatically preventing reclosure of said contacts, manual means for causing reclosure of saidjcontacts after operation of said reclosureprev'enting means, and means for positively rendering s-aid reclosure-preventing means operative to prevent contact reclosure in response to a first circuit interrupting operation closely following a manual reclosure after van automatic reclosurepreventing operation.

16. In an automatic reclosing circuit breaker having separable contacts, means responsive to predetermined circuit conditions for causing separation of said contacts to open the circuit, means responsive to a circuit interrupting operation for automatically causing a circuit closing operation of said contacts, means rendered operative in response to. apredetermined number of closely successive circuit interrupting operations for automatically preventing reclosure of said contacts, manual means for causing reclosure of said contacts after operation of said reclosure-preventing means, and means for positively rendering said reclosure-preventing means operative to prevent contact reclosure in response to a first circuit interrupting operation for a predetermined time following a manual reclosure after an automatic reclosure-preventing operation, whereby at the end of said predetermined time said reclosure-preventing means will again be responsive only to said predetermined number of operations.

17. In an automatic reclosing circuit breaker having separable contacts, meansresponsive to predetermined circuit conditions for causing separation of said contacts to open the circuit, means responsive to a circuit interrupting operation for automatically causing a circuit closing operation of said contacts, integrating means adapted to be advanced a predetermined amount in response to each operation of said breaker, said integrating means being biased to slowly return to its normal position, lockout means responsive to advancement of said integrating means an amount greater than said predetermined amount by a predetermined number of closely successive operations of said breaker for automatically preventing reclosure of the breaker contacts, manual means for causing reclosure of said contacts following automatic operation of said lockout means, and means effective when said contacts are prevented from reclosing for preventing return movement of said integrating means and being responsive to closing movement of said contacts to permit return movement of said integrating means.

18. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, resilient means for maintaining said contacts separated, overcenter toggle means for releasably maintaining said resilient means in an inactive condition, means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said resilient means whereby to maintain said contacts separated, one lever of said toggle means including an operating handle extension for resetting said toggle means, a casing for said circuit breaker having a hood portion positioned to normally receive said handle, and said handle being moved out of said hood portion by movement of said toggle overcenter to provide a clearly visible indication of the condition of said breaker when said contacts are maintained separated.

19. In an automatic reclosing circuit breaker, separable contacts, electro-responsive means for separating said contacts, means responsive to a circuit interrupting operation for automatically reclosing said contacts, biasing means for maintaining said contacts separated, overcenter toggle means for releasably maintaining said biasing means in an inactive condition, means responsive to a predetermined number of circuit interrupting operations to cause movement of said toggle means overcenter to release said biasing means whereby to maintain said contacts separated, manually operable means operatively associated with said toggle to reset the same, a casing for said circuit breaker having a hood @eeen-6e portion positioned tonormally'receive said manually operable means, and said manually operable means being moved out of said hood` portion by movement*l of'sad toggle overcenten to provide a clearly visible indication of the condition of.` saidbreaker when said'contacts are maintainedseparated.

JAMES M; WALLACE.l

HERBERT L. RAWLINS;

J AMES- M CUMMING;

WAYNES; ASPEY;

REFERENGES CITEDy The following references are of record` inthe` le of. this patent.:

1 UNITED. SIA'IES;` PATENTS Number Name Date 1 VThomson Nov: 14;` 11893- Number` 

